By-pass valve mechanism



Jan. 9, 1940. l R, EQ'UNG 2,186,015

BY-PASS VALVE MECHANISM Filed April 3, 1936 2 Sheets-Sheet 1 4 1 W50WWL@ 4/ l INVENTOR RALPH ERLING.

ATTORNEY Jan. Q, 1940. R, ERLlNG 2,186,015

BY-PASS VALVE MECHANI'ISM Filed April 3, 1936 2 Sheets-Sheet 2lNvr-:NTORl BY RALPH ERUNG.

ATTORNEY Patented Jan. 9, 1940 N alarms 'PATENT ortica l 2,186,015rvr-PASS VALVE MECHANISM.

Ralph Erima Cranford, N. J.

`Application April 3, 1936, Serial No. 72,658

. 6 claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370j. G. '757) This invention relates. to means foredualizing the pressure,at the end of a working stroke, in two cooperating cylinders of ahydraulic power mechanism so related functionally that one of .them issubjected to pressure while the other is subjected to suction.

Among the objects of this invention are: To provide valve means thatwill be automatically actuated at the end of a working stroke'tcequalize the pressures ci the pressure and suction sides of thehydraulic mechanism; to dispose the `said valve means in such mannerthat the proper valve vrudder post l?.

will be opened at the correct time by a member actuated by the hydraulicmechanism; to provide for connecting a valve in such relation that noypacking around the valve stem is required; to provide movementamplifying means to assure the sufcient throw of a valve ,operatedthereby.

In the drawings:

Figs, l and 2 illustrate my invention applied to asystem having twopairs oi hydraulic cylindersv and rams cooperating therewith;

Figs. 3 and 4 each shows the present invention associated with a singlepair of cylinders and Fig. discloses the valve opening means mounted onthe cross-head pin, the mechanism being shown in longitudinal section;

Figs'. 6 and 'l show motion amplifying means y to increase the throw ofthe valve; and

Figs. 8 and 9 are sectional views oi two forms of valve housings used inmy invention-` For convenience of description, the present invention isshown and described in connection with the steering gear of a ship, butit is to be K4understood that the subject device is useful in manyotherapplications 'of hydraulic mecha-gi nisms; 4 f

It is known to thoseiamiliar with the type of y hydraulic mechanism hereunder consideration that it is desirable to provide means for connectingthe pressure side of the mechanism to the suction side thereof at theend ci' each full work-y ing stroke to prevent damage to the mechanism yby driving any part thereof into -a stop under full power. The presentinvention aiords a simple and reliable system for accomplishing thisresult.

In Fig. l, the cylinders it and 'li are aligned and have a ram i2operable in both. Cylinders .I3 and Irl and ram l5 are disposed adjacentto cylinders lil and ll with their longitudinal axes parallel to thelongitudinal axes' ci the first mentioned cylinders, the rams It and i5being connected vtogether by a crosshead i6 securedon On cylinders and'I3 are 'mounted valve housings iii` le having in them chambersy 2c, ywith valves 215i and 25 seated in passages between the chambers in therespective housings. The Avalves 2i and 25 havey stems 25 and 2lprojectand 23, respectively,v

ing beyond the housings towards crosshead I6 with springs 2li on thestems' between the adjustable nuts 2t and the wall or" the housing toretain the valves seated.

Motor 29 drives reversible discharge pump 3l] to supply 'liquid underpressure to the system. Pipe Si connects the pump to cylinder l and pipe32 connects thepump to chamber 22 in housing It, whence the liquidpasses through vthepipe 33 to cylinder Il). Also, pipe 34 co-nnectsltheother side of pump 3l) to cylinder II while4 pipe 35 connects the sameside to chamber 2B iny housing i8, this chamber being connectedtocylinder i3 by pipe 3B. When the direction of uid delivery is reversedfrom that shown in Fig. l, it is obvious that vpipe 35 will be a highpressiue pipe instead of pipe 32 and it will be -further noted that bothof pipes 32 and 35 are connected to the chamber into which the respec`tive valve im or E5 is moved when unseated and,

therefore, the liquid under vpressure will hold the` valves upon theirseats and the springs 28 neednot rbe strong. Chambers 2l and 23 areconnected together by by-pass pipe 3l. A stop 38 is disposedtocheckmovement of the crcsshead at the end of 'each full stroke. rAs is' shownin Fig. 8, the seats 39 for the valvesj2ft and 25 may be `removed. afterdetaching end closure il!) of the' valvehousing and a newseat installedwhenever necessaryfduel to wear. Since the liquid in chamber 2l is neverunder high pressure, packing around valve stem 2t to prevent leakage of'fluid is not required, which' reducesl the cost of the valve assemblyand also the labor of replacing such packings when worn.

.It being assumed that pump 3i! is operated to cause movement of fluidas indicated by the arrows adjacent the several pipes, the rams l2 andl5 will be actuated in the directions shown by the arrowsl thereon. Atthe end oi the stroke, the lower (as seen in Fig. l) end of crossheadlli will push the stem-lll1 to unseat valve 25, 'which will permit theliquid under pressure to pass from chamber 22m" chamber whence it willgo' through pipe 3l', unseat valve 26E, and return to pump Bil throughchamber Zell and pipe 35, thus making the pressures in all the cylindersequal. If the crossheadshoul'd be continued lin motion lby the force ofva waveagainst the rudder or for any other reason, it will beeffectively checked upon Contact with stop 38. y

The mechanism shown in Fig. 2 is very similar to that in Fig. lexceptthat the cylinder housings' 'l the same reference characters.

Fig. 3 discloses the present invention applied to a single pair ofcylinders 4| and 42 with a cooperating ram 43. Fluid passes from pump 44through pipe 45 to chamber 46 in valve housing 41 and thence by pipe 48to cylinder 42. The re turn from cylinder 4| to pump 44 is through pipe49, chamber 50, and valve housing 5| and pipe |52. It is to beunderstood that reversal of the discharge of the pump will cause areversal in the flow of the liquid. The valve housings 41 and 5| have inthem chambers 52 and 53 connected by passages in which are seated valves54 and 55 with stems 55 and 5l attached thereto. These valves are heldseated by springs 58 on the valve stems as above described. Crosshead 59is oonnected to ram 43 and to a rotatable member, such as rudder post44. The limit stops in this figure are designated by 50. The pipe ||5connects chambers 52 and 59 and, therefore, when one of the valves, say54, is unseated the liquid) under pressure in pipe 45 will pass throughpipe ||5 to chamber 53, unseat valve 55 and return to the pump throughpipe |52. This action will, of course, be reversed when the discharge ofthe pump is reversed.

The form of invention illustrated in Fig. 4 is similar to that in Fig. 3with the exception of the Valve mechanism and, therefore, the partscommon to the two are given the same reference characters. The valvehousings 6| and 52 are connected to pump 44 by the pipes 45 and 52, butin this instance the chambers 03 and 54 that are directly connected tothe pump and are, therefore, under high pressure are so related tovalves 55 and G6 that the pressure from the pump tends to open theValves and the springs 51 are notl so strong as to prevent opening ofthe valves by the pressure. It follows, therefore, that when pipe 45 isthe pressure pipe, valve 55 will be held open and oil under pressurewill be present in chamber l0 but the effect of this pressure is to holdthe valve 55 seated. When crosshead 59 approaches the end of the strokeit contacts stem 1| of valve 56, opens that valve, and permits the fluidunder ressure in chamber 'I0 to move into chamber 64 and thence back tothe pump through pipe 52, thus effectively by-passing the cylinders andbringing the ram 49 to rest. Under conditions of reverse ow of liquid,the valve 66 will be held open and the pressure will be transmittedthrough pipe 'I2 to chamber 'I3 which pressure will be connected to thesuction side of the pump when crosshead 59 contacts stem 'E4 of valve65.

An enlarged sectional detail view of the valve construction employed inFig. 4 is disclosed in Fig. 9. The housing 9| has attached to it orformed integrally therewith an arm that is turned. over and providedwith an aperture in line with the opening in `the housing 6| throughwhich valve stem 'F4 passes and thus the arm serves as one abutment forspring 61 and also as a guide for the valve Stern 14. Inasmuch as thechamber 63 through one wall of which the valve stem passes is subjectedto high pressure, a packing gland T15 is provided to insure againstlealtage around stem '|4. The removable closure 40 and the replaceablevalve seat 39 are the same as in Fig. 8.

In Fig. 5 the cylinders 15 and 11 coact with the ram J8 to which thecrosshead 'F9 is connected by crosshead pin 30. The construction of thevalve housings in this gure and their manner of connection to the systemare the same as in Fig. 4 and the corresponding parts are, therefore,given On the crosshead pin is secured a member 8| having perforated ears82 into which are threaded bumper rods 83 and 84 each of which is heldagainst accidental shifting by a nut 85. The bumper rods are alignedwith valve stems 1| and 14 and serve to unseat the valves and by-passthe liquid from the pump at the end of a complete Working stroke.r

In some cases it is desirable to operate the bypass valves by armsmounted on the crosshead adjacent the rudder stock but difficulty hasbeen experienced heretofore in securing suflicient throw of the valveand the form of invention shown in Fig. 6 has, therefore, been devisedto cure this defect. Pump 86 is connected by pipes 8l and 88 to thechambers 89 and 90 in the valve housing 9| wherein a shuttle valve 92 ismounted in a passage between the two chambers. At each end of thehousing 9| is pivotally mounted a motion amplifying lever 93 having along arm 94 provided with an adjustable element 95 to contact valve stem95 and a shorter arm 91 lying at an angle to arm 94. The long arm 94 isprovided with an adjustable element disposed to be contacted by theadjustable bumper member 99 on arm |00 xed to crosshead |0|. When theparts are in the position shown, the output from pump 09 will flowthrough pipe 8B and pipe |02 to surround |03 while the returnfromcylinder |04 will pass through pipe |05 to pipe 81 and thence to thepump. However, when crosshead |0|, driven by ram |06 reaches the end ofits stroke the bumper member 99 will contact adjustable element 98 andswing the member 93 so that the member 95 will contact valve stern 89and, since the arc through which the member 95 moves is much greaterthan the arc described by arm 91, the movement imparted to member 98 isamplied and the shuttle valve 92 is quickly moved to the left a sufcientdistance to place the chambers 89 and 90 in free communication and,there-l fore, the output through pipe 08 merely circles through thevalve housing 8l and back to the pump through Apipe 81.

In Fig. 7 a somewhat similar arrangement is shown. The crosshead |0| hason it the arms |07 provided with a bumper element |08 which contacts onearm |09 of the pivoted double armed member l0 between the free end ofthe arm |09 and thepivot point thus making of the arm |09 a lever of thethird class and imparting to the free end of the arm a movement muchgreater than that of the member |08. The adjustable bumper member ismounted in arm |09 to contact stem 95 of the shuttle valve 92, the otherparts ofl the shuttle valve mechanism being the same as in Fig. 6.

It is to be understood that the motion amplifying means for operatingvalves described in the preceding two paragraphs may be applied toopening valves of other types than the shuttle valves herein used forpurpose of explaining the mode of operation of this mechanism.

It is to be noted that if the rudder is turned when the vessel is movingastern the pressure of the water on the rudder will tend to move it inthe same direction and will thereby reduce the pressure in the cylindersacting to put the rudder over and concomitantly will increase thepressure in the other cylinders since the iiuid in those other cylindersresist movement of the rudder by the water pressure. Under theseconditions, when a by-pass valve is opened by the cross head thepressure in the Working cylinder is insufcient to unseat the otherby-pass valve which is subjected to the greater pressure that lisresisting movement of the rudder by the water presure.

Consequently, the by-passing of the liquid cannot take place until thestops 38 or 60 prevent movement of the rudder by the water pressure,which permits the pump to withdraw fluid from the cylinders subjected tosuction and build up the pressure in the other cylinders suiiiciently tounseat the `Icy-pass valve not opened by the cross head, as is describedin my Patent 1,969,736.

The invention described and claimed herein may be manufactured and usedby or for the Government of the United States of America forgovernmental purposes without vthe payment of any royalties thereon ortherefor.

I claim: A

l. The combination with a mechanism that includes at least one pair ofaligned cylinders, a ram operable in the two cylinders of a pair, meansto supply fluid under pressure to one cylinder oi a pair andsimultaneously withdraw fluid from the other cylinder of the pair, acrosshead operatively connected to said ram, anda driven memberconnected to said crosshead; of a twochambered valve housing mounted oneach of two cylinders, saidA cylinders being operatively connectedthrough said housingsso that one cylinder receives `fluid under pressuresimultaneously with the withdrawal of iiuid from the other thereby atthe end of a stroke of said ram; means connecting to the cylinder uponwhich the other valve housing is mounted that chamber in each casinginto which the valve moves when unseated; means connecting each of thelast mentioned chambers to said iiuid supply means; and means connectingtogether the other two of said chambers, whereby when a valve isunseated the pressures in said cylinders are equalized.

2. The combination withk a mechanism thatincludes at least one pair ofaligned cylinders, a ram operable in the two cylinders of a pair, meansto supply vfluid under pressure to one cylinder of a pair andsimultaneously withdraw fluid from the other cylinder lof the pair, acrosshead operatively connected to said ram, and a driven memberconnected to said crosshead; of a twochambered valve housing associatedwith each of two cylinders, said cylinders being operatively connectedthrough said housings so that one cylinder receives fluid under pressuresimultaneously with the withdrawal of iluid from the other of said twocylinders, there being a passage between the chambers in each housing; avalve seat-ed in each of said passages and having a stem extendingtoward said cross head to be contactible thereby rat the end of a strokeofA said' simultaneously withdraw uid 'from the other cylinder, acrosshead operatively connected to said ram, and a driven memberconnected to said crosshead; of a two-chambered valve housing.

mounted on each of saidcylinders, there being a passage between the`chambers in each o f `said housings, a valve seated in each of saidpassagesy and having a stem extending beyond said housing to becontactible by said crossheadl substantially at the end of movement ofsaid ram, means connecting to the other cylinder that chamber in eachhousing into which the valve moves when it is unseated, means connectingthe llast mentioned chamber to the fluid supply means, and meansconnecting the other two of said chambers together.

, 4. The combination with a mechanism that includes two cylinders, meansto supply uid under pressure to either one lof said cylinders andsimultaneously to withdraw fluid from the other cylinder, means disposedin said cylinders to .be actuated by pressure therein and operativelyrelated to move simultaneously'in relatively opposite directions in therespective cylinders, and a crosshead operatively connected to said lastmentioned means; of fluid carrying means to connect said cylinderstogether, valve means connected between said iiuidsupply means and saidcylinders and between said cylinders normally conditioned to preventpassage of fluid from the cylinder receiving iiuid under pressure to theother cylinder, and slidable means .contactible by said crosshead tocondition said valve' means at a predetermined phase in the operation ofsaid mechanism to connect said cylinders together..

- 5. The combination with a mechanism that includes a pair of alignedcylinders, a ram operfluid under pressure to one of said cylinders andsimultaneously withdraw fluid from the other cylinder, a crossheadoperatively connected to said ram, and a driven member connected to saidcrosshead; yof a valve housing associated withl each of said cylinders,said housing having a flrst chamber and a second chamber with a passage-able in both of said cylinders, means to supply between said chambers,a valve seated in each of said passages to be movable into therespective first chamberv when unseated' and having a stem extendingthrough and beyond the second chamber, means connecting each of saidrstchambers to said iluid supply means, means connecting together saidsecond chambers, the pressure in said second chambers being alwaysrelatively low whereby the fit of said stem in the wall lof th-e chamberis suflicient to prevent leakage around said stem, said stems beingcontactible by said crosshead to unseat the valves.

6. The combination with a hydraulic power `mechanism that includes apair of aligned cylinders, a ram operable in both of said cylinders,

a crosshead operatively connected at one end to pivoted at one enddisposed to act upon said valve.

unseating meanswith its other end and contactible by an arm on saidcrosshead to actuate said member as a lever of the third class.

` RALPH ERLING.

